lovemyholden

Recipes 

Hello. How do you measure the alchohol content of homebrew? thanks in advance.

apparatus

Recipes 

1.) Use a hydrometer to measure the original gravity.
2.) Take a hydrometer reading to measure final gravity.
3.) Original gravity minus final gravity multiplied times 131 equals alcohol by volume.
Example: OG 1.050 - FG 1.012 = 38
38 X 131= 4.97 Alcohol by volume.

__________________
Apparatus

david_42

Recipes 

If you really want to know: purchase a heat-resistant 100 ml graduate cylinder and a good thermometer. Place EXACTLY 100 ml of ale in the cylinder (noting original temperature) and heat in a water bath until the ale reaches 78C. At this point, the alcohol will start to boil off and the temperature will stay at 78C until almost all of the alcohol is gone. When the temperature starts rising again, cool the cylinder to the original ale temperature (so the water shrinks to its original volume). Read the level and subtract from 100. That's your ABV.

If you have a really good scale, you can measure the weight change.

__________________
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"

"I would like to die on Mars, just not on impact." Elon Musk

Muntzster

Recipes 

Do you actually use that over the hydrometer?

david_42

Recipes 

No, but it does work.
A. I don't really care about ABV
B. I'm too lazy to do this routinely. I did it on my first cider because the gravity was under 0.990 and I didn't believe it: 8.5% from fresh pressed cider!

__________________
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"

"I would like to die on Mars, just not on impact." Elon Musk

Muntzster

Recipes 

So i shouldnt waste my money on one ?

veggiess

Recipes 

I am sure your parents will want to know the ABV of your brews, so have them buy you one. They can help you with the math.

chillHayze

Recipes 

The hydrometer method uses an approximation method which is usually on the high side if close at all. david42's method will tell you much more accurately the true content of a particular brew. It will cost 100mL of brew which is not acceptable by some people's standards. :-)

__________________
RDWHAHB
Every little thing is gonna be alright.